<html>
  <head>

  </head>

  <body>


  </body>

  <script>


let arr = ['a', 'b', 'c'];
let iter = arr[Symbol.iterator]();

console.log(iter)

console.log(iter.__proto__)

iter.next() // { value: 'a', done: false }
iter.next() // { value: 'b', done: false }
iter.next() // { value: 'c', done: false }
iter.next() // { value: undefined, done: true }



  </script>
</html>